I have a KB WV90 telly which is fitted with a tired A59-13W CRT, now I may have a chance of sourcing an A59-15W and wondered what the difference was and whether the two can be interchanged.I've found data for the A59-13W but can't find anything on the A59-15W, any ideas anyone ?

You have the information of the 13w with having the set and service manual. The info on the 15w should determine if it's a possiblity. Looking at the 15w the first thing to notice is it requires a seperate safety screen, either hard plastic, Fenbridge or safety glass. If the 13w has the safety glass built in or the Panorama type it would appear to not be suitable without sorting out the protection.

The A59-16W has integral implosion protection, I reckon tbe the 15W was intended to have a Fenbridge guard. So unless the safety aspect and mounting can be sorted out the 15w is not an easy replacement.https://frank.pocnet.net/sheets/030/a/A59-16W.pdfFrank

The original 13W is a push through twin wall and I note the KB state that a 23W with "inckit 1" can be used as a replacement.I think Frank is on the right track, it looks like the 15W may require a safety guard by the looks of things so not really suitable as a replacement for the 13W in terms of this KB WV90 shown below.

Oh well back to the waiting game for a 13 or 23 with kit....don't suppose anyone has one ?

Marc, as said in the earlier post an A59-16W is listed as an equivalent in the Mullard data book 1969 so that is one more to add to your search list along with CME2306 and possibly 11W and 12w as they are listed in the in the Radio valve and Semiconductor data book by Ball as having Rimguard protection.Chris

The 19" twin panel A47-13W and A59-13W tubes were initially marketed by Brimar and later by Mazda, which was also a Thorn-AEI company. Mazda types CME1906 and CME2306.Mullard also supplied these twin panel tubes, I'm not sure if the tubes were simply sourced from Brimar or if the company made the twin panel tubes. Mullard used the same type number, A47-13W.Later on in the late sixties Mullard offered the "IncKit" which was designed to the replace the old twin panel tube by employing the A47-26W, this tube employed a reinforced faceplate called by Mazda as Rimband III. The IncKit was expensive and I never used one as a replacement for my rental sets, preferring to buy rebuilt twin panel tubes instead. Anyway, by the mid seventies sets like the KB VV10 series were nothing more than just old tellies and considered not fit for reissue as rental sets.Attachment shows details of the Mullard IncKit system.